EP-4740285-A1 - ELECTROLYSIS CONTAINER, ELECTROLYSIS SYSTEM, METHOD FOR OPERATING AN ELECTROLYSIS SYSTEM, COMPUTER PROGRAM AND A CONTROLLER

EP4740285A1EP 4740285 A1EP4740285 A1EP 4740285A1EP-4740285-A1

Abstract

The present invention pertains to an electrolysis container (1) comprising a main power controller (2) and a plurality of electrolyzer stacks (3) that are connected to the main power controller (2) via a switching arrangement (4), wherein the main power controller (2) comprises a downscaled converter (7) and an upscaled converter (8) that are connected in parallel. If at least one electrolyzer stack (3) from the plurality of electrolyzer stacks (3) is disconnected from the main power controller (2) by means of the switching arrangement (4), the main power controller (2) only activates the downscaled converter (7) whereas only the upscaled converter (8) is activated when all electrolyzer stacks (3) are connected to the main power controller (2). This provides an upscaling and downscaling of the electrolysis container (1) for increasing the operating range to lower electrical power input (15) levels provided by a renewable electrical energy source (6).

Inventors

CRACIUN, BOGDAN
Runser, Thibaut
SCHUMANN, SVEN
BARTMANN, Andreas

Assignees

Siemens Energy Global GmbH & Co. KG

Dates

Publication Date: 20260513
Application Date: 20240801

Claims (1)

2023PF12108 - Auslandsfassung 36 Patent claims 1. Electrolysis container (1) comprising a main power con- troller (2) and a plurality of electrolyzer stacks (3) that are connected via a switching arrangement (4) to the main power controller (2) that is adapted to convert by means of a converter (5) an electrical power input (15) from an electri- cal energy source (6), particularly from a renewable electri- cal energy source (6), to an electrical power output (16) for the electrolyzer stacks (3), characterized in that the main power controller (2) is adapted to disconnect at least one electrolyzer stack (3) by means of a switching ele- ment (20) of the switching arrangement (4), wherein the con- verter (5) comprises a downscaled converter (7) and an up- scaled converter (8) and is adapted to activate only the downscaled converter (7) if at least one electrolyzer stack (3) is disconnected from the main power controller (2). 2. Electrolysis container (1) according to claim 1, charac- terized in that the downscaled converter (7) is adapted to output a downscaled electrical power output (16) and the up- scaled converter (8) is adapted to output an upscaled elec- trical power output (16), particularly a respective minimum electrical power for the electrolyzer stack (3) that is con- nected to the main power controller (2) to be operative. 3. Electrolysis container (1) according to one of the preced- ing claims, characterized in that the main power controller (2) is adapted to activate only the upscaled converter (8) if all electrolyzer stacks (3) are connected to the main power controller (2) and/or if none electrolyzer stack (3) is dis- connected from the main power controller (2). 4. Electrolysis container (1) according to one of the preced- ing claims, characterized in that the main power controller (2) is adapted to activate only the downscaled converter (7) if the electrical power input (15) from the electrical energy source (6) is below a second threshold value ( ^^ ^^ ^^ ଶ ) and/or 2023PF12108 - Auslandsfassung 37 the main power controller (2) is adapted to deactivate the downscaled converter (7) if the electrical power input (15) from the electrical energy source (6) is above the second threshold value ( ^^ ^^ ^^ ଶ ), and/or wherein the main power controller (2) is adapted to discon- nect at least one electrolyzer stack (3) from the main power controller (2) if the electrical power input (15) from the electrical energy source (6) is below the second threshold value ( ^^ ^^ ^^ ଶ ) or above the second threshold value ( ^^ ^^ ^^ ଶ ) and below a third threshold value ( ^^ ^^ ^^ ଷ ). 5. Electrolysis container (1) according to one of the preced- ing claims, characterized in that the main power controller (2) is adapted to activate the upscaled converter (8) if the electrical power input (15) from the electrical energy source (6) is above the second threshold value ( ^^ ^^ ^^ ଶ ) or above the third threshold value ( ^^ ^^ ^^ ଷ ) and/or the main power controller (2) is adapted to deactivate the upscaled converter (8) if the electrical power input (15) from the electrical energy source (6) is below the second threshold value ( ^^ ^^ ^^ ଶ ) or be- low the third threshold value ( ^^ ^^ ^^ ଷ ), wherein preferably the third threshold value ( ^^ ^^ ^^ ଷ ) is greater than the second threshold value ( ^^ ^^ ^^ ଶ ), and/or wherein the main power controller (2) is adapted to connect the at least one disconnected electrolyzer stack (3) to the main power controller if the electrical power input (15) from the electrical energy source (6) is above the second thresh- old value ( ^^ ^^ ^^ ଶ ) and/or below the third threshold value ( ^^ ^^ ^^ ଷ ). 6. Electrolysis container (1) according to one of the preced- ing claims, characterized in that the converter (5) further comprises a first polarization converter (9) and optionally the switching arrangement (4) is adapted to connect the dis- connected electrolyzer stack (3) to a second polarization converter (10), wherein the first and/or the second polariza- tion converter (10) is adapted to provide a polarization voltage for the respective electrolyzer stack (3). 2023PF12108 - Auslandsfassung 38 7. Electrolysis container (1) according to one of the preced- ing claims, characterized in that the electrolyzer stacks (3) are connected in series by means of the switching arrangement (4). 8. Electrolysis container (1) according to one of the preced- ing claims, characterized in that the main power controller (2) is adapted to measure the electrical power input (15) and/or is adapted to receive an electrical power input infor- mation from the electrical energy source (6), particularly a wind speed. 9. Electrolysis container (1) according to one of the preced- ing claims, characterized in that further comprising a backup gas processing unit (11) that is adapted to flush at least one electrolyzer stack (3) with an asphyxiant and/or an inert gas. 10. Electrolysis system (12) comprising at least one elec- trolysis container (1) according to one of the preceding claims. 11. Method for operating the electrolysis system (12) of claim 10 comprising an electrolysis container (1) of one of the claims 1 to 9 and further comprising at least one stand- ard electrolysis container (14) that comprises a main power controller (2) and an electrolyzer stack (3) and a converter (5), wherein the main power controller (2) is adapted to re- ceive an electrical power input (15) from an electrical ener- gy source (6), particularly a renewable electrical energy source (6), and is further adapted to provide an electrical power output (16) to the electrolyzer stack (3), comprising the steps of: ^ If the electrical power input (15) is below a sec- ond threshold value ( ^^ ^^ ^^ ଶ ) or above the second threshold value ( ^^ ^^ ^^ ଶ ) and below a third threshold value ( ^^ ^^ ^^ ଷ ), disconnect at least one electrolyzer stack (18) of the electrolysis container (1) from 2023PF12108 - Auslandsfassung 39 the main power controller (2) by means of the switching element (20) of the switching arrangement (4); ^ If the electrical power input (15) is below the second threshold value ( ^^ ^^ ^^ ଶ ), activate the downscaled converter (7) of the electrolysis con- tainer (1) and optionally deactivate the upscaled converter (8) of the electrolysis container (1). 12. Method according to claim 11, further comprising the steps of: ^ If the electrical power input (15) is above the second threshold value ( ^^ ^^ ^^ ଶ ) or above the second threshold value ( ^^ ^^ ^^ ଶ ) and below the third thresh- old value ( ^^ ^^ ^^ ଷ ), connect the at least one discon- nected electrolyzer stack (18) of the electrolysis container (1) to the main power controller (2) by means of the switching element (20) of the switch- ing arrangement (4); ^ If the electrical power input (15) is above the second threshold value ( ^^ ^^ ^^ ଶ ), deactivate the downscaled converter (7) of the electrolysis con- tainer (1) and optionally activate the upscaled converter (8) of the electrolysis container (1). 13. Method according to claim 11 or 12, further comprising the steps of: ^ If the electrical power input (15) is above the third threshold value ( ^^ ^^ ^^ ଷ ), activate the upscaled converter (8) of the electrolysis container (1) or deactivate the upscaled converter (8) if the elec- trical power input (15) is below the third thresh- old value ( ^^ ^^ ^^ ଷ ); ^ Optionally, activate the converter (5) of the re- spective standard electrolysis container (14) if the electrical power input (15) is above a first threshold value ( ^^ ^^ ^^ ^ ) of the respective standard electrolysis container (14) or deactivate the con- 2023PF12108 - Auslandsfassung 40 verter (5) if the electrical power input (15) is below the first threshold value ( ^^ ^^ ^^ ^ ), wherein the first threshold value ( ^^ ^^ ^^ ^ ) is preferably smaller than the third ( ^^ ^^ ^^ ଷ ) and/or the second threshold ^^ ଶ ). 14. Computer program comprising instructions which, when the program is executed by a computer, causes the computer to carry out the steps of the method of claims 11 to 13. 15. Controller for an electrolysis container (1), comprising a computer-readable storage medium having stored thereon the computer program of claim 14.

Description

2023PF12108 - Auslandsfassung 1 Description Electrolysis container, electrolysis system, method for oper- ating an electrolysis system, computer program and a control- ler Technical Field The invention relates to an electrolysis container, an elec- trolysis system, a method for operating an electrolysis sys- tem, a computer program and a controller. Technological Background Electrical power produced by means of a renewable electrical energy source such as a wind turbine or a solar power unit are produced in a stochastic and unpredictable manner and are therefore subject to variations in electrical power produc- tion. An efficient method for storing a surplus production of electrical power is by producing an energy carrier such as hydrogen by means of an electrolysis process. For a large- scale production, the electrolysis process is conducted by means of electrolysis containers. Particularly, decentralized hydrogen production comes with its own challenges concerning system stability and increased energy harvesting by means of hydrogen production. On the one hand, the renewable electri- cal energy source must produce a maximum amount of electrical energy provided by the environmental conditions such as wind speed and/or solar irradiation whereas on the other hand, a maximum amount of hydrogen needs to be produced in order to reduce a levelized cost of hydrogen (LCOH). However, variations of the production of electrical power due to the changing environmental conditions may cause the pro- duced electrical power to drop below a minimum level for the production of hydrogen. Thus, blind spots may occur in the production of hydrogen where no hydrogen is produced due to an amount of electrical power that is not sufficient due to a low wind speed and/or solar irradiation for instance. The topic of this application targets the avoidance of those 2023PF12108 - Auslandsfassung 2 blind spots for increasing the production of hydrogen or oth- er energy carriers. WO 2023/0644449A1 discloses a control system for operating a modular arrangement of electrolysis cells under variable in- put voltage conditions, such as those from renewable energy sources, to optimize operation by reducing under and overpo- tential of cells. Energy supply and electrolyte flow to cells or groups of cells is interrupted or resumed in response to available electrical potential and the optimal electrical po- tential required by active cells. The technical problem addressed in US 2022/389595 is how to efficiently produce hydrogen using a solar-powered electro- lyzer system, while maintaining power dissipation below a certain threshold. The patent describes various methods for controlling the current gain of the converter, which can ad- just the amount of hydrogen produced and the current at the electrolyzer stack. These methods include determining if hy- drogen production has decreased, if the current at the elec- trolyzer stack has increased, or if the power produced by the photovoltaic array is greater than a certain threshold. The patent also describes a method for increasing or decreasing the current gain of the converter based on these factors. Summary of the invention It is an object of the present invention to provide an im- proved electrolysis container with an increased operating range for the production of an energy carrier by means of re- newable energies. A solution is provided by the subject matter according to the independent claims. Advantageous additional embodiments of the invention are described by the dependent claims, the fol- lowing description and the Figures. The invention relates to an electrolysis container with the features of claim 1, comprising a main power controller and a 2023PF12108 - Auslandsfassung 3 plurality of electrolyzer stacks that are connected via a switching arrangement to the main power controller that is adapted to convert by means of a converter an electrical pow- er input from an electrical energy source, particularly from a renewable electrical energy source, to an electrical power output for the electrolyzer stacks, wherein the main power controller is adapted to disconnect at least one electrolyzer stack by means of a switching element of the switching ar- rangement, wherein the converter comprises a downscaled con- verter and an upscaled converter and is adapted to activate only the downscaled converter if at least one electrolyzer stack is disconnected from the main power controller. In other words, the main power controller may be adapted to output a direct current for the plurality of electrolyzer stacks, particularly the connected electrolyzer stack that may correspond to a minimum level of electrical power and/or an electrical voltage for the respective electrolyzer stack to be operative. The main power controller may be adapted to convert an alternating current or a direct current from an electrical network and/or the electrical energy source to the direct current for the plurality and/or a